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Geology 101 Final Exam

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Which one of the following aquifers would be best for purifying groundwater that is contaminated with harmful sewage bacteria?

a. clay

b. coarse gravel

c. sand

d. cavernous limestone

Which of the following rock materials would be least permeable?

a. coarse sand

b. clay-rich, fine‑grained sand

c. gravel

d. cavernous limestone

The major cause of most low‑latitude dry climates is:

a. their positions in the deep interiors of continents

b. the presence of high mountains that separate these areas from moist

maritime air masses

c. zones of high atmospheric pressure and dry descending air

d. none of the above

An open ocean wave has a wavelength of 20 meters, a wave height of 4 meters,

and a period of 6 seconds. At what depth will this wave begin to "feel

bottom"?

a. 1 meter

b. 2 meters

c. 10 meters

d. 15 meters

e. impossible to determine from the information given
because the wave moves half of the wavelength below the surface. therefore that is where the wave would begin to feel the ground.

A steep‑sided amphitheater‑shaped bowl, excavated by frost action

and glacial erosion, at the head of a glacial valley is called

a(n)

a. horn

b. arete

c. cirque

d. fjord

The dominant erosional force on Mercury is:

a. meteorite cratering

b. heat expansion

c. solar radiation

d. moonquakes

Which of the following is NOT found on Venus

a. prominent plateaus and basins

b. volcanoes

c. two-step topography

d. atmosphere

At a bend in a river, the main point of deposition is:

a. on the outside of the bend

b. on the inside of the bend

c. both outside and inside the bend

d. in the center of the channel

The downhill tilting of fences and telephone poles, and the presence of trees with curved trunks (convex downslope) are indications of what geologic process?

a. Debris avalanche

b. Slump

c. Soil creep

d. Gliding

e. Mudflow

Which of the following types of mass wasting is generally the slowest?

a. mudflow

b. creep

c. slump

d. they are all about the same

mass wasting events are caused by

1) Over-steepening of slope,

2) Too much water, and

3) Unusual rock/soil conditions.

ways to mitigate mass wasting dangers?

-Steep slopes can be covered or sprayed with concrete covered with a wire mesh to prevent rock falls.

-Retaining walls could be built to stabilize a slope. 


-If the slope is made of highly fractured rock, rock bolts may be emplaced to hold the slope together and prevent failure.

-Drainage pipes could be inserted into the slope to more easily allow water to get out and avoid increases in fluid pressure, the possibility of liquefaction, or increased weight due to the addition of water.

-Oversteepened slopes could be graded to reduce the slope to the natural angle of repose. -In mountain valleys subject to mudflows, plans could be made to rapidly lower levels of water in human-made reservoirs to catch and trap the mudflows.

slump A form of mass wasting event that occurs when loosely consolidated materials or rock layers move a short distance down a slope.
slide Rocks moving rapidly along a surface parallel to slope.
flow Material moves as fluid.
collecting phase The upper part has numerous tributaries, is actively down-cutting the land (eroding), and tends to have V-shaped channels.
transporting phase is highly meandering, has fewer tributaries and is not down-cutting and eroding sediment but moving it like a conveyor belt. The river in this phase may be either braided (with a broad flat channel) or meandering (with a semicircular channel).
dispersing phase is the delta where the rivers sediment is dumped into a body of water and gradually extends the river and eventually (if you wait long enough) fills the bay.
oxbow lake Because rivers erode at the outside of the bend, they are constantly changing shape and cutting off loops creating oxbow lakes.
braided river is one of a number of channel types and has a channel that consists of a network of small channels separated by small and often temporary islands called braid bars
flood plain Is flat or nearly flat land adjacent to a stream or river that experiences occasional or periodic flooding.
types of mass wasting: PHOTO
photo
Stream: PHOTO
photo
dependance on ground water? It provides about 40% of our water nationally. However, it takes many years to replenish itself
how much of worlds water is fresh? 2%
problem when wells are over pumped? Pumping a well in an unconfined aquifer will produce a cone of depression around the well. ( Occurs in an aquifer when groundwater is pumped from a well. In an unconfined (water table) aquifer, this is an actual depression of the water levels. In confined (artesian) aquifers, the cone of depression is a reduction in the pressure head surrounding the pumped well.)
zone of aeration The subsurface sediment above the water table containing air and water.
recharge hydrologic process where water moves downward from surface water to groundwater. This process usually occurs in the vadose zone below plant roots and is often expressed as a flux to the water table surface.
sinkhole A natural depression or hole in the surface topography caused by the removal of soil or bedrock, often both, by water.
how do glaciers erode? They erode because they carry rocks and grit in their bases and their great weight grinds these rocks into the underlying bedrock.
features caused by glaciers They are tremendous eroders and will straighten, deepen and round out V-shaped valleys which were originally carved by rivers
firn It is ice that is at an intermediate stage between snow and glacial ice. Firn has the appearance of wet sugar, but has a hardness that makes it extremely resistant to shovelling.
zone of accumulation Above the snowline where accumulation of snow exceeds evaporation and melting.
zone of ablation Below the snowline where evaporation and melting exceed accumulation, has crevasses.
terminus The end of the glacier.
erratic A piece of rock that differs from the size and type of rock native to the area in which it rests.
striations Scratches or gouges cut into bedrock by process of glacial abrasion.
alpine glacier

Tongue shaped glaciers in mountains.

continental glacier Large ice sheets covering large areas. They are more or less round or elliptical in shape and have a central zone of accumulation surrounded by the zone of ablation kind of like a large sunny side up egg.
crevasse A crack in an ice sheet or glacier.
cirque Bowl-shaped depressions on the side of mountains.
horn A mountaintop that has been modified by the action of ice during glaciation and frost weathering.
glacial trough (u-shaped valley) A deep U-shaped valley with steep sides that leads down from a cirque and was excavated by a glacier.
hanging valley A tributary valley with the floor at a higher relief than the main channel into which it flows.
Arete A thin, almost knife-like, ridge of rock which is typically formed when two glaciers erode parallel U-shaped valleys.
fjord If you fill the glacial trough above with water you get a fjord.
till Unsorted glacial sediment.
moraine Any glacially formed accumulation of unconsolidated glacial debris (soil and rock) which can occur in currently glaciated and formerly glaciated regions, such as those areas acted upon by a past ice age.
why deserts form where they do Deserts occur in two parallel bands centered at around 25 degrees latitude. This distribution is because of atmospheric cells that create a dry high pressure system over these areas pretty much permanently.
why deserts are windy There is a lot of wind in deserts because they tend to have very hot temperatures in the day and cool temperature at night. This usually causes lots of air to move and blow things around. Most wind erosion is causing by wind moving silt and fine sand grains in zone about a meter above the ground.
effects of wind erosion Wind erosion causes a typical desert feature known as desert pavement. This is caused when wind removes fine grains and leaves a residual rock pavement. This process is called deflation.
barchan dune Arc shaped sand dune with two downward pointing ends.
barchanoid dune Where there is more sand and the barchans coalesce into something like a line.
transverse dune A transverse dune is perpendicular to the prevailing wind, probably caused by a steady build-up of sand on an already existing minuscule mound.
star dune A dune that has slip faces on three or more sides, which is formed by multiple wind directions.
ventifact Rocks that have been abraded, pitted, etched, grooved, or polished by wind-driven sand or ice crystals.
flash flood A rapid flooding of geomorphic low-lying areas - washes, rivers, dry lakes and basins. It is caused by heavy rain associated with a storm, hurricane, or tropical storm.
alluvial fan Formed where a fast flowing stream flattens, slows, and spreads typically at the exit of a canyon onto a flatter plain.
breakwater structures constructed on coasts as part of coastal defence or to protect an anchorage from the effects of weather and longshore drift.
groin

A structure that juts out into a body of water perpendicular to the shoreline and is built to restore an eroding beach by intercepting longshore drift and trapping sand.

drowned coast A shoreline transformed from a hilly land surface to an archipelago of small islands by inundation by the sea.
wave refraction When waves approach an irregular shoreline, those approaching headlands (parts of the coast that stick out) feel bottom and slow before those that are heading towards indentations in the shore. This causes the waves to wrap around coastal features.
tsunami

which are usually generated by earthquakes, are odd in that they have very long wavelengths and low wave heights and very high speed. In the open ocean they have very low heights (a foot or so) and are usually not even noticed by boats. But their wavelengths are so large that they feel bottom in fairly deep water, far offshore and they therefore have a long way in which to build a tremendous wave height. Under the right conditions a tsunami can reach a hundred feet or more.

wave of oscillation open ocean wave
wave of translation waves that are breaking